AT89C5132 Atmel Corporation, AT89C5132 Datasheet - Page 51

• Manufacturer Part Number: AT89C5132
• Manufacturer: Atmel Corporation

Specifications of AT89C5132

• Flash (kbytes): 64 Kbytes
• Max. Operating Frequency: 20 MHz
• Cpu: 8051-12C
• Max I/o Pins: 44
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 1
• Uart: 1
• Adc Channels: 2
• Adc Resolution (bits): 10
• Adc Speed (ksps): 22.7
• Sram (kbytes): 2.25
• Self Program Memory: API
• Operating Voltage (vcc): 2.7 to 3.6
• Timers: 2
• Isp: UART/USB
• Watchdog: Yes

12.3.2
Figure 12-4. Timer/Counter x (x = 0 or 1) in Mode 1
Figure 12-5. Mode 1 Overflow Period Formula
12.3.3
Figure 12-6. Timer/Counter x (x = 0 or 1) in Mode 2
Figure 12-7. Mode 2 Autoreload Period Formula
12.3.4
4173E–USB–09/07
Mode 1 (16-bit Timer)
Mode 2 (8-bit Timer with Auto-Reload)
Mode 3 (Two 8-bit Timers)
INTx
INTx
CLOCK
CLOCK
TIMx
TIMx
Tx
Tx
TMOD Reg
TMOD Reg
GATEx
GATEx
÷ 6
÷ 6
Mode 1 configures Timer 0 as a 16-bit Timer with TH0 and TL0 registers connected in cascade
(see Figure 12-4). The selected input increments TL0 register. Figure 12-5 gives the overflow
period calculation formula when in timer mode.
Mode 2 configures Timer 0 as an 8-bit Timer (TL0 register) that automatically reloads from TH0
register (see Table 42). TL0 overflow sets TF0 flag in TCON register and reloads TL0 with the
contents of TH0, which is preset by software. When the interrupt request is serviced, hardware
clears TF0. The reload leaves TH0 unchanged. The next reload value may be changed at any
time by writing it to TH0 register. Figure 12-7 gives the autoreload period calculation formula
when in timer mode.
Mode 3 configures Timer 0 such that registers TL0 and TH0 operate as separate 8-bit Timers
(see Figure 12-8). This mode is provided for applications requiring an additional 8-bit Timer or
TMOD Reg
TMOD Reg
C/Tx#
C/Tx#
0
1
0
1
TCON Reg
TCON Reg
TRx
TRx
TFx
PER
TFx
=
PER
6
=
⋅
(65536 – (THx, TLx))
6
⋅
(256 – THx)
(8 Bits)
F
F
TIMx
TIMx
THx
(8 Bits)
(8 Bits)
THx
TLx
(8 Bits)
TLx
Overflow
Overflow
TCON Reg
TCON Reg
TFx
TFx
AT89C5132
Timer x
Interrupt
Request
Timer x
Interrupt
Request
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